fix(#875): make getMilestonePhaseFilter fence-aware (#880)

Closes #875

.changeset/875-getmilestonephasefilter-fence-aware.md

@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 880
+---
+`getMilestonePhaseFilter` now excludes phase headings inside fenced code blocks (``` ``` ``` or `~~~`) — consistent with the fence-aware behavior of `extractCurrentMilestone`. Previously, a `### Phase N:` line inside a fenced block was wrongly counted as a real phase. (#875)

src/roadmap-parser.cts

@@ -327,6 +327,46 @@ function getMilestoneInfo(cwd: string): MilestoneInfo {
   }
 }
 
+// ─── Fence-aware text helper ──────────────────────────────────────────────────
+
+/**
+ * Return a copy of `text` with every line that lies inside a fenced code block
+ * replaced by an empty string, using the same fence semantics as
+ * `computeSectionEnd` (backtick/tilde, ≥3 chars, indent ≤3 spaces, toggle;
+ * an unclosed fence treats remaining content as fenced).
+ */
+function stripFencedLines(text: string): string {
+  let fenceChar: string | null = null;
+  let fenceLen = 0;
+  const lines = text.split('\n');
+  const result: string[] = [];
+  for (const line of lines) {
+    const fm = line.match(/^\s{0,3}((?:`{3,}|~{3,}))(.*)/);
+    if (fm) {
+      const ch = fm[1][0];
+      const ln = fm[1].length;
+      const trailing = fm[2] || '';
+      if (!fenceChar) {
+        fenceChar = ch;
+        fenceLen = ln;
+        // The fence-open line itself is not a content line — blank it.
+        result.push('');
+      } else if (ch === fenceChar && ln >= fenceLen && /^\s*$/.test(trailing)) {
+        fenceChar = null;
+        fenceLen = 0;
+        // The fence-close line — blank it.
+        result.push('');
+      } else {
+        // A fence marker that doesn't close the current fence (different char or shorter) — keep treating as fenced content.
+        result.push(fenceChar ? '' : line);
+      }
+    } else {
+      result.push(fenceChar ? '' : line);
+    }
+  }
+  return result.join('\n');
+}
+
 // ─── Milestone phase filter ───────────────────────────────────────────────────
 
 type MilestonePhaseFilter = ((dirName: string) => boolean) & {
@@ -416,8 +456,9 @@ function getMilestonePhaseFilter(cwd: string, versionOverride?: string | null):
     }
 
     const phasePattern = /#{2,4}\s*(?:\[[^\]]+\]\s*)?Phase\s+([\w][\w.-]*)\s*:/gi;
+    const roadmapUnfenced = stripFencedLines(roadmap);
     let m: RegExpExecArray | null;
-    while ((m = phasePattern.exec(roadmap)) !== null) {
+    while ((m = phasePattern.exec(roadmapUnfenced)) !== null) {
       milestonePhaseNums.add(m[1]);
     }
   } catch { /* intentionally empty */ }

tests/roadmap-parser.test.cjs

@@ -467,7 +467,7 @@ describe('roadmap-parser: getMilestonePhaseFilter', () => {
     assert.strictEqual(filter.phaseCount, 1, 'deduplication: only 1 unique phase');
   });
 
-  test('adversarial: characterizes current fence-blind behavior for backtick fence (pending #875)', () => {
+  test('adversarial: phase heading inside backtick fence is excluded (fix #875)', () => {
     writeRoadmap(tmpDir, [
       '## v1.0: Real',
       '```',
@@ -478,10 +478,10 @@ describe('roadmap-parser: getMilestonePhaseFilter', () => {
     ].join('\n'));
 
     const filter = getMilestonePhaseFilter(tmpDir);
-    // KNOWN BUG #875: getMilestonePhaseFilter is fence-blind — phase headings inside
-    // fenced code blocks are incorrectly parsed as real phases. Flip to false when #875 is fixed.
+    // Phase headings inside fenced code blocks must NOT be counted as real phases.
+    // getMilestonePhaseFilter is fence-aware (fix #875).
     assert.strictEqual(filter('01-real'), true, 'real phase matches');
-    assert.strictEqual(filter('999-fake'), true, 'characterization: getMilestonePhaseFilter is currently fence-blind (KNOWN BUG #875) — flip to false when #875 is fixed');
+    assert.strictEqual(filter('999-fake'), false, 'fenced phase heading is correctly excluded');
   });
 
   test('adversarial: unclosed fence block — does not crash', () => {
@@ -501,7 +501,7 @@ describe('roadmap-parser: getMilestonePhaseFilter', () => {
     assert.ok(typeof filter === 'function', 'filter is a function');
   });
 
-  test('adversarial: characterizes current fence-blind behavior for tilde fence (pending #875)', () => {
+  test('adversarial: phase heading inside tilde fence is excluded (fix #875)', () => {
     writeRoadmap(tmpDir, [
       '## v1.0: Tilde',
       '~~~',
@@ -511,10 +511,35 @@ describe('roadmap-parser: getMilestonePhaseFilter', () => {
     ].join('\n'));
 
     const filter = getMilestonePhaseFilter(tmpDir);
-    // KNOWN BUG #875: getMilestonePhaseFilter is fence-blind — phase headings inside
-    // tilde-fenced code blocks are incorrectly parsed as real phases. Flip to false when #875 is fixed.
+    // Phase headings inside tilde-fenced code blocks must NOT be counted as real phases.
+    // getMilestonePhaseFilter is fence-aware (fix #875).
     assert.strictEqual(filter('01-real'), true, 'real phase matches despite tilde fence');
-    assert.strictEqual(filter('999-fake'), true, 'characterization: getMilestonePhaseFilter is currently fence-blind (KNOWN BUG #875) — flip to false when #875 is fixed');
+    assert.strictEqual(filter('999-fake'), false, 'tilde-fenced phase heading is correctly excluded');
+  });
+
+  test('adversarial: phase heading inside fence is excluded with CRLF endings (fix #875)', () => {
+    const crlf = '## v1.0: CRLF Fence\r\n```\r\n### Phase 999: Fake\r\n```\r\n### Phase 1: Real\r\n';
+    writeRoadmap(tmpDir, crlf);
+    const filter = getMilestonePhaseFilter(tmpDir);
+    assert.strictEqual(filter('01-real'), true, 'real phase matches in CRLF file');
+    assert.strictEqual(filter('999-fake'), false, 'fenced phase excluded in CRLF file');
+  });
+
+  test('adversarial: phase headings in back-to-back fences are excluded (fix #875)', () => {
+    writeRoadmap(tmpDir, [
+      '## v1.0: Adjacent',
+      '```',
+      '### Phase 998: Fake A',
+      '```',
+      '```',
+      '### Phase 999: Fake B',
+      '```',
+      '### Phase 1: Real',
+    ].join('\n'));
+    const filter = getMilestonePhaseFilter(tmpDir);
+    assert.strictEqual(filter('01-real'), true, 'real phase matches');
+    assert.strictEqual(filter('998-fake'), false, 'first fenced phase excluded');
+    assert.strictEqual(filter('999-fake'), false, 'second fenced phase excluded');
   });
 
   test('adversarial: CRLF line endings in roadmap', () => {